For people who are using the coins appropriately, i.e. just in the course of playing the game, doing strikes, and quests etc. I don't think the drop rates are too high. The farmers on level 14 bosses are the issue (if you want to call it an issue. If people want to play the same thing over and over who who cares) Its really simple fix if you want to stop farmers: Don't allow the exhaustion a 3 of coins buff if you are fighting the same boss you exhausted your last 3 of coins buff on within a certain time frame. Don't let farmers ruin this for everyone else.